1. Field of the Invention
The present invention relates to a discharge lamp unit. In particular, the present invention relates to a discharge lamp unit including a supporting member that supports a discharge lamp and a circuit board that supplies power to the discharge lamp.
2. Description of the Related Art
Conventionally, a discharge lamp unit is designed taking into consideration heat conduction within the discharge lamp. For example, in Japanese Patent Laid-open Publication No. 2003-022702, as the above-described discharge lamp unit, a technology is disclosed in which the material used to form a casing that houses a circuit board is changed to a material that does not easily conduct heat to inhibit conduction of heat generated by a discharge lamp to the circuit board.
However, in the above-described discharge lamp unit, the casing member is heated by radiant heat induced by the discharge lamp. Even when the material used to form the casing member is changed to a material that does not easily conduct heat, the heat generated by the discharge lamp tends to reach the circuit board when the casing member is continuously heated over a long period.
In light of the above-described problem, an object of the present invention is to provide a technology for further inhibiting heat generated by the discharge lamp from reaching the circuit board in a discharge lamp unit.